500 poly are the max that is acceptable for a tree ... if you need more then you should consider replacing parts of the leaf sections with better textures that you for example could obtain through rendering that part of the tree.
As you perhaps saw on WoW screens etc, a forest which can be passed, is only possible with lowpoly trees with good texturing.
As you perhaps saw on WoW screens etc, a forest which can be passed, is only possible with lowpoly trees with good texturing.